Imagine traveling from Seattle to Portland in half the time it takes to get from downtown Seattle to Bellevue in rush-hour traffic. A University of Washington team of 35 engineering students is working to make this a reality with Hyperloop, a transit system that could zip Seattleites to Stumptown at up to 760 mph

For the past four years, from Sodo to South Lake Union, a 9,270-foot underground dig has unfolded to bring Seattle the world’s largest tunnel, part of the $3.1 billion replacement of the Alaskan Way Viaduct. The tunnel ($2 billion of that), while beset by not-inconsiderable setbacks, is also a project marked by engineering marvels on a Brobdingnagian scale. Take an underground tour with our exclusive photo essay.